1. Field of the Invention
This invention relates generally to electrical switching apparatus, and more particularly, to an operating mechanism for a fluid blast circuit interrupter.
2. Description of the Prior Art
Conventionally, during the opening operation of a fluid blast circuit interrupter, the arc established between the separating breaker contacts of the interrupter is extinguished by a blast of high pressure, arc-extinguishing gas, which, when directed orthogonally to the arc for elongation and cooling thereof, transforms the conductive arcing path into an insulating medium as the alternating current passes through current zero. Generally, such circuit interrupters include a high pressure gas valve for supplying the arc-extinguishing gas from a high pressure gas reservoir, which valve must be operated in synchronism with the breaker contacts. For example, U.S. Pat. No. 3,956,605, issued May 11, 1976, to Roidt et al, discloses a fluid blast circuit interrupter in which the opening of the high pressure gas valve is coordinated with the opening of the interrupter contacts by using a rotatable cam plate to individually actuate both the high pressure valve and the interrupter contacts in a variable and predetermined manner.